Conventional methods of crop farming require that a field to be planted is first plowed, then harrowed, then raked and then planted and then cultivated. Additional operations such as fertilizing, applying herbicide, discing and the like require additional trips to the field. Normally each operation requires a separate pass over the field by a tractor towing appropriate equipment, thereby requiring as many as six passes over a field to raise a single crop. Obviously, the conventional technique requires the expenditure of great amount of time on the part of the farmer, as well as a great expenditure of money in terms of fuel and energy involved in the multiple passes through the field.
The prior art has proposed different types of apparatus and different methods by which more than one of the foregoing operations could be accomplished in a single pass. Such prior art includes U.S. Pat. No. 2,577,363 and U.S. Pat. No. 3,110,275 and U.S. Pat. No. 3,372,657, all of which describe apparatus and methods to accomplish some tillage in combination with the planting operation. Other combinations of apparatus have been assembled, but none of the prior art devices have achieved commercial adoption.